EPA-99-E3S4-02-03

099

1,480 千元

2010/01/01

2010/12/31

紀凱獻

環檢所

李慈毅

中央研究院

大氣空氣、環境監測及檢測

戴奧辛；大氣沈降；底泥泥芯

Dioxin；Deposition；Sediment core

張木彬、高樹基

紀凱獻

02-26539885#256

khchi@rcec.sinica.edu.tw

本研究針對北台灣翡翠水庫、中台灣日月潭及南台灣曾文水庫等水庫/湖泊背景水源區進行大氣戴奧辛沈降量、湖泊底泥及湖泊水體量測，進而建立戴奧辛於國內背景環境受體中之累積、轉化速率與沈降量之關聯性。研究結果顯示北台灣背景水源區大氣戴奧辛平均濃度為13.610 fg I-TEQ/m3，中台灣大氣戴奧辛平均濃度為15.65.2 fg I-TEQ/m3而南台灣大氣戴奧辛平均濃度為10.96.3 fg I-TEQ/m3，此外，北台灣戴奧辛沈降通量介於0.950至38.5 pg I-TEQ/m2/day，中台灣介於0.613至2.95 pg I-TEQ/m2/day而南台灣則介於0.206至2.42 pg I-TEQ/m2/day之間，綜觀而論以南台灣背景水源區最低。水體觀測結果顯示，北台灣翡翠水庫、中台灣日月潭及南台灣曾文水庫表層水體(水深: 0.5 m)戴奧辛平均濃度為0.0100.001、0.0100.003及0.0080.001 pg WHO-TEQ/L，其南北差異並不大，初步推論翡翠水庫、日月潭及曾文水庫表層水中戴奧辛濃度呈現均勻分布之特性。泥芯檢測數據顯示，翡翠水庫、日月潭及曾文水庫泥芯戴奧辛輸入通量分別為9.18 pg I-TEQ/m2/day、2.54 pg I-TEQ/m2/day及26.5 pg I-TEQ/m2/day，若與大氣戴奧辛沈降通量交叉計算，可獲致上游流域沿岸土壤沖刷戴奧辛輸入貢獻分別為40%、44%及95%。因此，若水體上游流域之土壤受到污染並累積大量的戴奧辛時，其將透過下雨沖刷以及地表逕流將戴奧辛往下游移動進而累積至末端之水庫/湖泊底泥中。若要確實掌握台灣水庫/湖泊戴奧辛之來源特性，進行全國性之戴奧辛土壤普查工作實屬必要，方能確切掌握台灣本土戴奧辛污染特性進而評估相關戴奧辛排放減量策略之具體管制成效。

戴奧辛；大氣沈降；底泥泥芯

期末報告（修訂稿）.pdf

5MB

計畫結案報告

2011/2/1 上午 12:00:00

In this study, polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) levels and depositions in ambient air, water column and sediment were measured at background area of reservoir-watershed systems in Northern (Feitsui Reservoir), Central (Sun Moon Lake) and Southern (Tsengwen Reservoir) Taiwan from January 2008 to 2010.The results indicated that the atmospheric PCDD/F concentrations measured in the vicinity area of Feitsui Reservoir, Sun Moon Lake and Tsengwen Reservoir ranged were 13.610, 15.65.2 and 10.96.3 fg I-TEQ/m3, respectively. In addition, the PCDD/F deposition flux measured in the same area were ranged from 0.950~38.5, 0.613~2.95 and 0.206~2.42 pg I-TEQ/m2/day, respectively. The atmospheric PCDD/F concentrations and deposition fluxes measured at the background area in Southern Taiwan were considerably lower than those measured in this study. The sampling results also indicated that the PCDD/F levels in the surface water (water depth: 0.5 m) measured in Feitsui Reservoir, Sun Moon Lake and Tsengwen were 0.0100.001, 0.0100.003 and 0.0080.001 pg WHO-TEQ/L, respectively. The results indicated that the PCDD/F concentrations in the surface water were uniform and sufficiently mixed at different locations in the reservoir. The results conducted from sediment measurements indicated that the PCDD/F input flux to the reservoir were 9.18, 2.54 and 26.5 pg I-TEQ/m2/day in Northern, Central and Southern Taiwan, respectively. Based on the mass calculations, around 40 to 95% of the PCDD/F input flux was contributed by catchment erosion. These findings implied that the pollutants deposited in the watershed must be transported to the reservoir by typhoon runoff and related physical erosion and that both of these phenomena play a major role in PCDD/F accumulation in the downstream reservoir.

Dioxin；Deposition；Sediment core